[THE ROLE OF STREPTOMYCES NOGALATER Lv65 snoaM, snoaL and snoaE GENES IN NOGALAMYCIN BIOSYNTHESIS].

The results of phylogenetic analysis indicate high similarity of SnoaM, SnoaL SnoaE to the cyclases involved in the biosynthesis of various antibiotics. Genes snoaM, snoaL and snoaE disruption in S. nogalater chromosome was carried on and S. nogalater MI, LI and EI strains were generated. The gene replacement events in M1, L1 and E1 were verified by Southern hybridization. Recombinant strains were characterised by lack of nogalamycin biosynthesis. Originally, M1, L1 and E1 were complemented with plasmids expressing putative cyclase genes from S. nogalater leading to restoration of nogalamycine production. The complementation results clearly indicate that obtained strains are cyclase deficient mutants. Furthermore, complementation of M1, L1 and E1 with a cyclase genes from wild-type strain is consistent with the suggested function of these enzymes.

Neonatal cholestasis with increased 3ß-monohydroxy-Δ5 bile acids in serum and urine: not necessarily primary oxysterol 7α hydroxylase deficiency.

BACKGROUND: Inborn errors of bile acid synthesis are rare genetic disorders that can present with cholestatic liver disease. Recently we encountered 3 infants with neonatal cholestasis and excessive 3ß-monohydroxy-Δ5-C24 bile acids in serum and urine. We investigated whether identification of 3ß-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol in serum and urine of cholestatic patients is necessary for diagnosis of primary oxysterol 7α-hydroxylase deficiency. METHODS: These 3 patients initially led us to suspected oxysterol 7α-hydroxylase deficiency. However, sequence analysis of genomic DNA resulted in diagnosis of 2 patients with oxysterol 7α-hydroxylase deficiency and 1 patient with 3ß-hydroxy-Δ5-C27-steroid dehydrogenase/isomerase deficiency. We examined identification of 3ß-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol by gas chromatography-mass spectrometry after diagnosis. RESULTS: Interestingly, we detected a peak for 3ß-hydroxy-5-cholestenoic acid in serum and 27-hydroxycholesterol of the neutral sterol in urine from 2 patients who were diagnosed with primary oxysterol 7α-hydroxylase deficiency. CONCLUSION: In evaluating infants with cholestasis and excessive 3ß-monohydroxy-Δ5-C24 bile acids in infancy, one needs to conduct C24 bile acid analysis serially. Results can guide performance and interpretation of genomic DNA analysis. Moreover, identification of 3ß-hydroxy-5-cholestenoic acid in serum and 27-hydroxycholesterol in urine is highly important for diagnosis of oxysterol 7α-hydroxylase deficiency as is genomic DNA analysis.

Production host selection for asymmetric styrene epoxidation: Escherichia coli vs. solvent-tolerant Pseudomonas.

Selection of the ideal microbe is crucial for whole-cell biotransformations, especially if the target reaction intensively interacts with host cell functions. Asymmetric styrene epoxidation is an example of a reaction which is strongly dependent on the host cell owing to its requirement for efficient cofactor regeneration and stable expression of the styrene monooxygenase genes styAB. On the other hand, styrene epoxidation affects the whole-cell biocatalyst, because it involves toxic substrate and products besides the burden of additional (recombinant) enzyme synthesis. With the aim to compare two fundamentally different strain engineering strategies, asymmetric styrene epoxidation by StyAB was investigated using the engineered wild-type strain Pseudomonas sp. strain VLB120ΔC, a styrene oxide isomerase (StyC) knockout strain able to accumulate (S)-styrene oxide, and recombinant E. coli JM101 carrying styAB on the plasmid pSPZ10. Their performance was analyzed during fed-batch cultivation in two-liquid phase biotransformations with respect to specific activity, volumetric productivity, product titer, tolerance of toxic substrate and products, by-product formation, and product yield on glucose. Thereby, Pseudomonas sp. strain VLB120ΔC proved its great potential by tolerating high styrene oxide concentrations and by the absence of by-product formation. The E. coli-based catalyst, however, showed higher specific activities and better yields on glucose. The results not only show the importance but also the complexity of host cell selection and engineering. Finding the optimal strain engineering strategy requires profound understanding of bioprocess and biocatalyst operation. In this respect, a possible negative influence of solvent tolerance on yield and activity is discussed.

Peroxisomal L-bifunctional enzyme (Ehhadh) is essential for the production of medium-chain dicarboxylic acids.

L-bifunctional enzyme (Ehhadh) is part of the classical peroxisomal fatty acid ß-oxidation pathway. This pathway is highly inducible via peroxisome proliferator-activated receptor α (PPARα) activation. However, no specific substrates or functions for Ehhadh are known, and Ehhadh knockout (KO) mice display no appreciable changes in lipid metabolism. To investigate Ehhadh functions, we used a bioinformatics approach and found that Ehhadh expression covaries with genes involved in the tricarboxylic acid cycle and in mitochondrial and peroxisomal fatty acid oxidation. Based on these findings and the regulation of Ehhadh's expression by PPARα, we hypothesized that the phenotype of Ehhadh KO mice would become apparent after fasting. Ehhadh mice tolerated fasting well but displayed a marked deficiency in the fasting-induced production of the medium-chain dicarboxylic acids adipic and suberic acid and of the carnitine esters thereof. The decreased levels of adipic and suberic acid were not due to a deficient induction of ω-oxidation upon fasting, as Cyp4a10 protein levels increased in wild-type and Ehhadh KO mice.We conclude that Ehhadh is indispensable for the production of medium-chain dicarboxylic acids, providing an explanation for the coordinated induction of mitochondrial and peroxisomal oxidative pathways during fasting.

Docosahexaenoic acid mediates peroxisomal elongation, a prerequisite for peroxisome division.

Peroxisome division is regulated by several factors, termed fission factors, as well as the conditions of the cellular environment. Over the past decade, the idea of metabolic control of peroxisomal morphogenesis has been postulated, but remains largely undefined to date. In the current study, docosahexaenoic acid (DHA, C22:6n-3) was identified as an inducer of peroxisome division. In fibroblasts isolated from patients that carry defects in peroxisomal fatty acid ß-oxidation, peroxisomes are much less abundant than normal cells. Treatment of these patient fibroblasts with DHA induced the proliferation of peroxisomes to the level seen in normal fibroblasts. DHA-induced peroxisomal proliferation was abrogated by treatment with a small inhibitory RNA (siRNA) targeting dynamin-like protein 1 and with dynasore, an inhibitor of dynamin-like protein 1, which suggested that DHA stimulates peroxisome division. DHA augmented the hyper-oligomerization of Pex11pß and the formation of Pex11pß-enriched regions on elongated peroxisomes. Time-lapse imaging analysis of peroxisomal morphogenesis revealed a sequence of steps involved in peroxisome division, including elongation in one direction followed by peroxisomal fission. DHA enhanced peroxisomal division in a microtubule-independent manner. These results suggest that DHA is a crucial signal for peroxisomal elongation, a prerequisite for subsequent fission and peroxisome division.

[A newly discovered metabolic diseases due to defects in the pentose pathway]. / Nowo opisane choroby metaboliczne zwiazane z bledami metabolizmu na szlaku przemiany pentoz.

Two previously unreported inborn errors of metabolism occur in the reversible part of the pentose phosphate pathway. Deficiency of ribose-5-phosphate isomerase has been described in one patient who suffered from a progressive leukoencephalopathy and developmental delay. Transaldolase deficiency has been diagnosed in 11 patients from 6 families in which the probands presented in the newborn and antenatal period with hepatospIenomegaly, hemolytic anaemia, hepatic fibrosis, kidney problems. Enzymes deficiency results in accumulations in body fluids erythritol, arabitol, ribitol, sedoheptitol, sedoheptulose, sedoheptulose-7-phosphate. Isomerase and transaldolase activity can be determined in leukocytes or fibroblasts.

Titration of bile acid supplements in 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency.

OBJECTIVES: 3beta-Hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency is a bile acid synthesis defect responsive to primary bile acids. We reviewed its clinical features and response to treatment with a mixture of ursodeoxycholic (UDCA) and chenodeoxycholic acid (CDCA) to titrate the dose of supplements required for disease control. PATIENTS AND METHODS: We studied our patients by liquid chromatography-tandem mass spectrometry, liver function tests, and histology. After diagnosis all of the patients received a balanced mixture of UDCA/CDCA and the dose was titrated according to urinary levels of 3beta,7 alpha-dihydroxy-5-cholenoic acid (u-3beta-D-OH-5C). RESULTS: Five patients presenting with giant cell hepatitis, biliary cirrhosis, and cryptogenic cirrhosis (1 each), and picked up by neonatal screening (2 patients) were diagnosed at a median age of 2.5 years (range 0.1-5.5). Normal levels of u-3beta-D-OH-5C were achieved after 4 months (range 3-28 months) from the start of the treatment. The minimum dose of UDCA/CDCA required to maintain normal u-3beta-D-OH-5C levels was 5/5 mg x kg(-1) x day(-1). A follow-up biopsy in 2 patients showed no progression of liver disease. CONCLUSIONS: A mixture of UDCA/CDCA can effectively control 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase/isomerase deficiency. Dose titration by liquid chromatography-tandem mass spectrometry warrants the maintenance of negative feedback on the abnormal synthetic pathway and avoids disease progression.

Red cell glycolytic enzyme disorders caused by mutations: an update.

Glycolysis is one of the principle pathways of ATP generation in cells and is present in all cell tissues; in erythrocytes, glycolysis is the only pathway for ATP synthesis since mature red cells lack the internal structures necessary to produce the energy vital for life. Red cell deficiencies have been detected in all erythrocyte glycolytic pathways, although their frequencies differ owing to diverse causes, such as the affected enzyme and severity of clinical manifestations. The number of enzyme deficiencies known is endless. The most frequent glycolysis abnormality is pyruvate kinase deficiency, since around 500 cases are known, the first of which was reported in 1961. However, only approximately 200 cases were due to mutations. In contrast, only one case of phosphoglycerate mutase BB type mutation, described in 2003, has been detected. Most mutations are located in the coding sequences of genes, while others, missense, deletions, insertions, splice defects, premature stop codons and promoter mutations, are also frequent. Understanding of the crystal structure of enzymes permits molecular modelling studies which, in turn, reveal how mutations can affect enzyme structure and function.

Changes in the amounts of myelin lipids and molecular species of plasmalogen PE in the brain of an autopsy case with D-bifunctional protein deficiency.

Changes in the molecular species of lipids associated with peroxisomal d-bifunctional protein (d-BP) deficiency were investigated in cerebral tissues to elucidate the pathological mechanisms underlying this disorder. Total phospholipids in the gray and white matters of the patient's brain were decreased to approximately 73% and 50% of control levels, respectively, and profound declines in myelin lipids, i.e. galactosyl ceramide and sulfatides, indicated dysmyelination in our patient with d-BP deficiency. Although the total ganglioside amounts in the gray and white matter of this patient's brain were also decreased to 61% and 37% of control levels and GM1 in the white matter was 20% of the control level, the relative amounts of GM2 in both the gray and the white matter of this patient's brain were increased in comparison to those in the control, indicating altered metabolism of gangliosides. In addition, among molecular species of phospholipids, plasmalogen-type and polyunsaturated fatty acid-containing phosphatidylethanolamine were characteristically decreased in the patient's gray matter. These alterations in the molecular species of brain lipids may affect sensitivity to oxidative stress and the membrane fluidity of neural cells, thereby producing the brain pathology of d-BP deficiency.

[Peroxisomal D-bifunctional enzyme deficiency. A case report]. / Deficencia enzimática D-bifuncional peroxlsomal. Caso clínico.

Newborn was referred with diagnosis of neonatal epilepsy. Medical team could suspect and confirm D-bifunctional peroxisomal enzymatic deficiency diagnosis. It was made by family antecedents, severe neonatal hypotonia, uncontrolled neonatal seizures, craniofacial dysmorphic features, psychomotor retardation, neuronal migration defect and a positive peroxisomal panel. The full study in skin fibroblasts involved enzyme analysis, complementation studies and DNA analysis. The accumulation of very long chain fatty acids, partial deficiency in phytanic acid oxidation, and abnormal morphology of peroxisomes was consistent with a defect in peroxisomal fatty acid oxidation, involving D-bifunctional protein. It is very important to make a diagnosis of this innate error of metabolism in order to give preconceptional genetic counseling, to identify recurrence risk and to perform mutation analysis for the D-bifunctional protein gene, and to offer the prenatal diagnosis.

Aberrant peroxisome morphology in peroxisomal beta-oxidation enzyme deficiencies.

Peroxisomes are ubiquitous organelles in eukaryotic cells and surrounded by a single membrane, and undergo considerable changes in size, shape and number. Peroxisomal disorders are classified into two categories: peroxisome biogenesis disorders (PBDs) and single-enzyme deficiencies (SEDs). Morphologically aberrant peroxisomes called 'peroxisomal ghosts' in PBDs are well known, however, a morphological approach to the study of peroxisomes in SEDs has been rarely reported. Here, we investigated the morphology of peroxisomes in cultured fibroblasts from patients lacking peroxisomal beta-oxidation enzymes, including acyl-CoA oxidase (AOX) or D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (D-BP). Morphological analysis by immunofluorescence examination using an antibody against catalase revealed a smaller number of large peroxisomes in fibroblasts from these patients. Moreover, immunoelectron microscopy using an antibody against the 70-kDa peroxisomal membrane protein (PMP70) showed large peroxisomes with various horseshoe-shaped membrane structures. These results give an important clue to elucidating the division of peroxisomes and how peroxisomes change in size, shape, number and position within cells, which are subjects for future study.

Clinical and biochemical spectrum of D-bifunctional protein deficiency.

OBJECTIVE: D-bifunctional protein deficiency is an autosomal recessive inborn error of peroxisomal fatty acid oxidation. Although case reports and small series of patients have been published, these do not give a complete and balanced picture of the clinical and biochemical spectrum associated with this disorder. METHODS: To improve early recognition, diagnosis, prognosis, and management of this disorder and to provide markers for life expectancy, we performed extensive biochemical studies in a large cohort of D-bifunctional protein-deficient patients and sent out questionnaires about clinical signs and symptoms to the responsible physicians. RESULTS: Virtually all children presented with neonatal hypotonia and seizures and died within the first 2 years of life without achieving any developmental milestones. However, within our cohort, 12 patients survived beyond the age of 2 years, and detailed information on 5 patients with prolonged survival (> or =7.5 years) is provided. INTERPRETATION: Biochemical analyses showed that there is a clear correlation between several biochemical parameters and survival of the patient, with C26:0 beta-oxidation activity in cultured skin fibroblasts being the best predictive marker for life expectancy. Remarkably, three patients were identified without biochemical abnormalities in plasma, stressing that D-bifunctional protein deficiency cannot be excluded when all peroxisomal parameters in plasma are normal.

Optico-cochleo-dentate degeneration associated with severe peripheral neuropathy and caused by peroxisomal D-bifunctional protein deficiency.

The clinical, neuroradiological, neuropathological and biochemical findings in a patient with optico-cochleo-dentate degeneration (OCDD; OMIM 258700) are presented in a severe case succumbing at the age of 4 years. The electron microscopic and biochemical data showed for the first time that OCDD may occur as the phenotypic expression of D-bifunctional protein deficiency, i.e., a peroxisomal disorder. The boy was born as the first child of healthy, consanguineous parents of Turkish origin. No other family members were affected. The main clinical symptoms consisted of muscle hypotonia ("floppy infant"), generalized epileptic fits, hypacusis, rotatory nystagmus, insufficient pupillary reactions, and mental retardation. Fibroblast cultures revealed D-bifunctional protein deficiency. Neuropathological examination displayed moderate frontoparietal and insular microgyria, and atrophy of the cerebellum. Loss of neurons was severe in the granular layer, the Purkinje cell band of the cerebellum, and rather complete in the dentate nucleus. A corresponding loss of myelinated fibers associated with characteristic periodic acid-Schiff-positive macrophages was most prominent in the white matter of the cerebellum. There was additional severe loss of myelinated fibers in the central portions of the optic nerve, reduction of the nerve fiber density in the cochlear nerve, and reduction of myelinated nerve fibers by about 80-90% in the sural nerve, which has not been studied in previous cases. At the electron microscopic level, characteristic inclusions mainly in perivascular macrophages and astrocytes were the most prominent finding. The inclusions usually showed a bilaminar structure, whereas trilaminar structures, typically seen in adrenoleukodystrophy, and multilaminar structures were less frequently seen.

Peroxisomal Delta3-cis-Delta2-trans-enoyl-CoA isomerase encoded by ECI1 is required for growth of the yeast Saccharomyces cerevisiae on unsaturated fatty acids.

We have identified the Saccharomyces cerevisiae gene ECI1 encoding Delta3-cis-Delta2-trans-enoyl-CoA isomerase that acts as an auxiliary enzyme in the beta-oxidation of (poly)unsaturated fatty acids. A mutant devoid of Eci1p was unable to grow on media containing unsaturated fatty acids such as oleic acid but was proficient for growth when a saturated fatty acid such as palmitic acid was the sole carbon source. Levels of ECI1 transcript were elevated in cells grown on oleic acid medium due to the presence in the ECI1 promoter of an oleate response element that bound the transcription factors Pip2p and Oaf1p. Eci1p was heterologously expressed in Escherichia coli and purified to homogeneity. It was found to be a hexameric protein with a subunit of molecular mass 32, 000 Da that converted 3-hexenoyl-CoA to trans-2-hexenoyl-CoA. Eci1p is the only known member of the hydratase/isomerase protein family with isomerase and/or 2-enoyl-CoA hydratase 1 activities that does not contain a conserved glutamate at its active site. Using a green fluorescent protein fusion, Eci1p was shown to be located in peroxisomes of wild-type yeast cells. Rat peroxisomal multifunctional enzyme type I containing Delta3-cis-Delta2-trans-enoyl-CoA isomerase activity was expressed in ECI1-deleted yeast cells, and this restored growth on oleic acid.

Glycerol production in a triose phosphate isomerase deficient mutant of Saccharomyces cerevisiae.

Interesting challenges from metabolically engineered Saccharomyces cerevisiae cells arise from the opportunity to obtain yeast strains useful for the production of chemicals. In this paper, we show that engineered yeast cells deficient in the triose phosphate isomerase activity are able to produce glycerol without the use of steering agents. High yields of conversion of glucose into glycerol (80-90% of the theoretical yield) and productivity (1.5 g L-1 h-1) have been obtained by a bioconversion process carried out in a poor and clean medium. We obtained indications that the growth phase at which the biomass was collected affect the process. The best results were obtained using cells collected at the end of exponential phase of growth. In perspective, the strategies and the information about the physiology of the cells described here could be useful for the developing of new biotechnological processes for glycerol production, outflanking the problems related to the use of high level of steering agents.

Peroxisomal bifunctional enzyme complex deficiency with associated retinal findings.

Peroxisomal bifunctional enzyme complex deficiency is a recently recognized abnormality of fatty acid metabolism. We herein present the association of a flecked retina with peroxisomal bifunctional enzyme deficiency, a clinical association not previously reported. We suggest the finding of a flecked retina in an infant presenting with hypotonia, seizures, and failure to thrive is highly suggestive of this diagnosis.

Novel subtype of peroxisomal acyl-CoA oxidase deficiency and bifunctional enzyme deficiency with detectable enzyme protein: identification by means of complementation analysis.

We describe four infants with a novel subtype of an isolated deficiency of one of the peroxisomal beta-oxidation enzymes with detectable enzyme protein. The patients showed characteristic clinical and biochemical abnormalities, including hypotonia, psychomotor retardation, hepatomegaly, typical facial appearance, accumulation of very-long-chain fatty acids, and decreased lignoceric acid oxidation. However, beta-oxidation enzyme proteins were detected by immunoblot analyses, and large peroxisomes were identified by immunofluorescence staining. In order to identify the underlying defect in these patients, complementation analysis was introduced using fibroblasts from these patients and patients with an established deficiency of either acyl-CoA oxidase or bifunctional enzyme, as identified by immunoblotting. In the complementing combinations, fused cells showed increased lignoceric acid oxidation, resistance against 1-pyrene dodecanoic acid/UV selection, and normalization of the size and the distribution of peroxisomes. The results indicate that two patients with a more severe clinical course were suffering from bifunctional enzyme deficiency and that the other two infants, who were siblings and had a less severe clinical presentation, were the first patients with acyl-CoA oxidase deficiency with detectable enzyme protein.